Carbon black dispersions and carbon-silver combinations as thermal pastes that surpass commercial silver and ceramic pastes in providing high thermal contact conductance

Carbon black dispersions are superior to the best commercial silver and ceramic particle thermal pastes for providing high thermal contact conductance across mating surfaces that are smooth (0.05 μm). For mating surfaces that are rough (15 μm), the combined use of carbon black and silver is more effective than carbon, silver or ceramic pastes. The use of a silver paste to even out the rough surfaces prior to using the carbon black dispersion is more effective than the use of a carbon-silver mixture. For both smooth and rough surfaces, the carbon-silver mixture is superior to silver pastes. The highest conductance attained for rough surfaces is lower than that attained for smooth surfaces.